The present invention relates to an improved dried egg white which exhibits improved water retention, gel strength, elasticity, and the like after reconstitution and heat coagulation, while imparting excellent quality-improvement effects when used in various foods without adversely affecting the flavor and the like of the foods, to a method for producing the improved dried egg white, and to foods containing the improved dried egg white.
Since dried egg whites can be preserved for a long period of time, and require only low transport cost and a small shelf space as compared with raw egg whites, the dried egg whites are used as ingredients of various foods. In order to prevent quality deterioration such as browning and giving off an unpleasant odor during storage due to the Maillard reaction which occurs between the amino groups in egg proteins and glucose in egg white during preservation, the dried egg whites are prepared by desugaring liquid egg whites and drying the desugared egg whites by various methods such as spray drying, pan drying, freeze drying, and vacuum drying. Desugaring is typically carried out using yeasts, enzymes, bacteria, and the like. Since an appropriate range of pH during the desugaring treatment is weakly acidic to neutral, the pH is typically adjusted during desugaring by the addition of an acid agent such as citric acid. The resulting egg whites thus typically have an approximately neutral pH.
Dried egg whites are used not only as egg white ingredients, but also as quality-improving agents for improving the yield and texture of various processed foods such as processed meat products, processed seafood products, and noodles. Heat-coagulated products (gels) produced by coagulating dried egg whites by heating to be used for these applications are desired to exhibit high water retention, high gel strength, elasticity, and the like. For this reason, dried egg whites with improved properties such as water retention, gel strength, and elasticity have heretofore been proposed.
Japanese Patent No. 3244586, for example, proposes a dried egg white with improved elasticity obtained by adding a fatty acid. However, the dried egg white obtained using this technique may have an unpleasant taste and odor due to the fatty acid.
JP-A-11-266836 proposes a dried egg white with improved water retention obtained by adjusting the pH of a liquid egg white to 9.3 or more by the addition of an alkali salt such as sodium carbonate, maintaining the egg white at this pH for 10 minutes, and by drying the egg white. With this technique, however, because the alkali salt added remains in the final product, the addition of the resulting dried egg white to a food may adversely affect the taste or physical properties of the food.